Charles steteeeldt



` dtted ,Sinai-e5,

CHARLES STETEFELDT, OIF-AUSTIN, NEVDA.'

Letters Patent No. 100,337, dated Mft/rch 1, 1870.

IMPRovED MACHINE FOR FEEDING oREs IivTo sHAT noAsTING-PUR'NAcEs.

The Schedule referred to m these Letters'Paten't and making part of the same.

To all. whom it 'ma-y concern.-

Be it known that I, CHARLES STTEFELDT, of Austin, in the county of Lauder, and State of Nevada, have invented a new and improved Machine for Feeding Ores into Shaft Roasting-Furnaces; land I do hereby declare the. following` to be a full,- clear, and exact description thereof, which will enable others skilled .in the art to which-it appertaius to make and use my invention, reference being had to the accompanying drawings which form. a part of this specitication, and in which- Figure lis a longitudinal, and

Figure 2 a transverse section of my improved feeding machine, taken on the line n n, tig. 1.

Figure 3 is a plan view of the punched screen, and Figure 4 is a perspective view of the water-box. The same parts are denoted by the s aine letters in both the figures.

My invention is designed to be employed inconnection with a shalt furnace inwhich ore is roasted or treated by dropping it in a' finely pulverzed state down lthe shaft.

A A'represent a hollow water-box of cast-iron or other suitable material, the space between whose sides is. kept constantly iilledwith water, which is forced in through the lower pipe a, and flows out through the upper pipe b.' Between the two pipes there is a partition, as shown at c; This box is made with a shoulder, as shown at e, to receive the frame or grating B of the punched screen C. This screen. may be made of any suitable material and degree`- of tineness. 1, prefer to make it of the ineness known as No. 0, made of Russia iron, or copper, or of steel, and used in wet crushing.

D 1) is an upper screen of coarse wire, which I prefer to make o i iron or copper, or of steel, and of the fineness known in the trade asA No. 3. The screen, however, may be made of any other suitable material and degree ofvfneness. This screen is fastened in the frame E,- from each corner of which projects an arm, F, resting on the frictiou-roller f,'so that the wire screen is suspended ou the lriction-rollelslby means oi' the four arms F F F F, and at such a height as almost to touch the punched screen.

Two of the armsF F arel connected by a rod, g, and a reciprocating movement is imparted to the frame-of.

the wire screen by means of the crank and pitman, as shown, or by any other suitable devices.

` The screens C and Dare nclosed withina hopper,

G, ou the sides of which are bearings hh, for the crossbars H H. These, bars are almost in contact with the top of the wire screen.

The operation is as follows:

The pulp from the dry-crushing battery is intro-4 duced into the hopper, and falls on the coarse wire screen, to which a rather slow reciprocating motion is imparted. I have found it best to give the driving pulley t' a speed of from thirty to seventy revolutions per minute. The movement of this screen carries the pulp against the bars, by which it is held so as to be' cut by the wires of the screen, and the wire screen being pressed down by' the weight of the pulppupon it so asrto be in contact with the punched screen, threes the pulp through the holes in the latter, whence it lfalls down the shaft. l During thisoperation the heating and warping of the screens and other metal parts are prevented by the constant circulation of cold water through the water-box, the cold water being forced through Vthe lower pipe, and the heated water escaping through the upper.

I "make the lower screen punched instead of constrp'cting'it ot' wire, because it 4is necessary, in order to forcethe pulp through it, that it should. be in contact with the upper screen. lhe lower screen, therefore, must -not sag nnderthe weight of' the pulp, which' a wire 'screen will-always do.

The screens are readily detachable. so 'that either may beat once replaced.

What I claim as new, and desire to secure by Letters Patentofthe United States, ,is-

1. The combination of the punched screen, the wire screen moving close toit, and the bars.

2. The combination kof the bars, ,wire screen, and punched screen, with the water-box, all operating as described.

3. The combination of the bars and wire screen, op-

erating as described.

' CHARLES STETEFELDT.

Witnesses:

WM. J. BURNS, WM. R. WRIGHT. 

